Charles Grant, director of think-tank The Centre of European Reform, said Macron's position was that there "must be a price to pay" for leaving the EU.

But he said Macron's predecessor's position was just as hardline and the new president's "kudos, eloquence, ability to persuade" could lessen the "serious risk" of Britain leaving the EU without a deal.

"Any deal on Brexit will require somebody to knock heads together and forge a compromise," Grant told HuffPost UK.

"Merkel is that person but she's weaker than she was. If you look around the table there isn't anyone of any stature at all.

"Donald Tusk can knock heads together but he's too timid. He can sort of gently nudge them a bit closer together. That's all he can do. [Jean-Claude] Juncker has no credibility with the Brits."

Grant said he expected the 39-year-old Macron to be "the EU's next Blair", adding: "He will walk on water, at least for a couple of years. He'll be incredibly influential.

"Having another European leader who can forge compromises, in addition to Merkel, is useful."

Grant also cited Macron's links to Britain. He visited as recently as February, when he spoke at Downing Street, and addressed Grant's think-tank in London in November.

When he was still economics minister in Francois Hollande's government, he called Britain "a great country".

"It's better to have someone who's hard [on Brexit] and understands us, who's intelligent, rather than some European politicians who are hard, less intelligent and don't understand us," Grant said.